JPS61118724A - Optical shutter array element - Google Patents

Abstract

PURPOSE:To lower a driving voltage and to eliminate a secular change of an element due to long-period driving by forming electrodes and an insulating resin film on a groove wall surface provided on plate type light transmissive ceramic and a flat plate connecting with it. CONSTITUTION:A polarizer 15 is irradiated with light from behind and a voltage is applied between a voltage application electrode group 13 and a common electrode 12 formed on the PLZT flat plate 11, so that the applied part changes in polarization state and the light is transmitted. Electrodes are formed on the groove wall surface for electrode arrangement and the surface of the flat plate 11 connecting with it to prevent an electric field from being applied to a part B which is easily congested, and the insulating resin film 14 makes a part C hard to strain mechanically, thereby eliminating deterioration at the parts B and C. Therefore, while the driving voltage is lowered, deterioration of the element due to long-period driving is eliminated and the reliability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a solid-state optical shutter array element that can be used in optical control equipment, such as writing devices in optical printers, high-speed optical shutters in cameras, and the like.

Conventional configurations and their problems In recent years, the development of optical-related technologies such as optical communication and optical information processing has been very active, and as a result, optical components,
The development of optical control devices is gaining importance. Among these, solid translucent porcelain having an electro-optical effect can also be used as an optical shutter as a light control device, and is expected to have various applications. In particular, the optical shutter elements formed in an array are expected to be applied as a writing head for an optical printer, which is a type of non-impact printer that has recently been attracting a lot of attention.

Currently, what is known as the above-mentioned optical shutter array element is La-doped lead zirconate titanate (PLZ).
±46° with respect to the direction of the electric field vector that occurs when a voltage is applied to the electrodes on a flat plate of translucent porcelain such as T), which has a plurality of electrodes symmetrically on the front and back sides, or on at least one side. It has a structure in which it is sandwiched between polarizing plates having a polarization axis of °.

However, in the surface electrode structure as described above, when a voltage is applied to the element, the electric field concentrates on the electrode end and the surface, resulting in poor driving efficiency and high applied voltage.

Therefore, a structure has been proposed in which a groove is provided in the electrode forming portion and an electrode is provided on the wall surface of the groove, thereby making it possible to drive at a low voltage. A conventional optical shutter array element will be described below with reference to the drawings.

The tortoise in FIG. 1 shows a configuration diagram of a conventional optical shutter array element, in which 1 is a PLZT flat plate, 2 is a common electrode provided on the PLZT flat plate 1, and 3 is a group of voltage application electrodes. 4 is a polarizer, and 5 is an analyzer, which are arranged in the direction of ±46° with respect to the direction of the electric field vector generated when a voltage is applied between the common electrode 2 and the voltage application electrode group.
The polarization axes are configured to be orthogonal to each other. Figure 1.

This is a cross-sectional view of the space between Eiro in FIG. 1a.

As is clear from the figure, the electrodes provided on the PLZT flat plate are provided with grooves on the surface of the PLZT flat plate 1, and are formed on the side and bottom surfaces of the grooves.

The operation of the conventional optical shutter array element configured as shown in the figure will be described below.

Figure 1a When light is irradiated from the rear of polarizer 4, PLZ
When no voltage is applied between the voltage application electrode group 3 formed on the T-plate 1 and the common electrode 2, birefringence due to the electro-optic effect does not occur, and the polarizer 4 and analyzer 5 is blocked, but when a voltage is applied to the voltage application electrode group 3, birefringence occurs due to the Kerr effect of the electro-optic effect,
The polarization state of the light changes and the light is transmitted. Therefore, by applying a voltage to any electrode in the voltage application electrode group 3, light from any part can be transmitted, and by placing a photoconductor or the like in front of the analyzer 6, any pattern can be created. It can be used as a writing head for non-striking optical printers. In addition, since the electrode portion is formed on the wall surface of the groove, the voltage applied between the common electrode 2 and the voltage application electrode group 3 can be reduced. It is.

However, the PLZT electro-optic material not only has a large Kerr effect as an electro-optic effect.

When an electric field is applied, there is a large phenomenon (electrostrictive phenomenon) that causes distortion proportional to the square of the electric field, and in the conventional electrode structure as shown in Fig. 1 a and b, the part shown in Fig. 1 is a groove wall surface;
The electric field tends to concentrate on the intersection lines on the surface of the PLZT flat plate 1, and furthermore, from the top of the structure, the strain due to the electrostrictive phenomenon concentrates on the areas where the lines intersect, making it easy to cause mechanical breakdown, which is different from conventional elements. The structure had a problem in that it deteriorated over time due to repeated voltage changes of 0N10FF.

OBJECT OF THE INVENTION The object of the present invention is to provide an optical shutter array element which is very effective when used as a light control device such as an optical printer, has a low driving voltage, and has excellent reliability with little change over time due to long-term operation. It is to provide.

Structure of the Invention An optical shutter array element is provided with a plurality of electrodes, and polarizing plates are arranged on the front and back sides of the flat plate so that the polarization axes make an angle of 90° with each other, the electrode of the plate-shaped transparent porcelain. A groove for electrode placement is provided at the placement position, the electrode is formed over at least the groove wall surface and the plate-shaped translucent porcelain surface connected to the groove wall surface, and the electrode portion and an optical shutter connected thereto are provided. The optical shutter array element has a structure in which resin is formed over a part of the part, and thereby the optical shutter array element can be driven at a low voltage and has excellent long-term reliability.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 2a and 2b show the structure of an optical shutter array element in an embodiment of the present invention.

In Figures 2a and b, 11 is a PLZT flat plate, 12 is a P
A common electrode is provided on the LZT flat plate 11, and 13 is a group of electrodes for voltage application. 14 is an electrode part on a PLZT flat plate;
An insulating resin is formed over the negative part of the optical shutter section connected to the reed, 16 is a polarizer, and 16 is an analyzer. ±4 relative to the direction of the electric field vector
It is configured to have a polarization axis in a direction of 5°. FIG. 2 shows a cross-sectional view between Eiro in FIG. 2a.

The operation of the optical shutter array element of this embodiment configured as described above will be described below.

The principle of the optical shutter array element having the configuration according to the present invention is the same as that of the optical shutter array element having the conventional configuration, and FIG. When light is irradiated from the rear of the polarizer L15, when no voltage is applied between the voltage application electrode group 13 formed on the PLZT flat plate 11 and the common electrode 12, birefringence due to the electro-optic effect is However, when a voltage is applied to the voltage application electrode group 13, the polarization state of the light changes only in the portion to which the voltage is applied, and the light is transmitted. However, in the case of the embodiment according to the present invention, as can be seen from the cross-sectional view of FIG.
If the electric field is not applied to the part B in Fig. 2 (same as the M part in Fig. 1), where strain due to electrostriction phenomenon tends to concentrate and mechanical damage is likely to occur, and the part 8 is not distorted, At the same time, by forming resin on the electrode end portion C in Figure 2, it is possible to mechanically prevent strain.
This alleviates the stress caused by the sudden difference in strain that occurs at the electrode ends. This is part 8.

By eliminating deterioration at the 0 part and making the electrode part a buried type as in the past, an effective electric field is applied also in the thickness direction, making it possible to realize low voltage driving. As described above, with the structure of this example, it was possible to realize an optical one-shutter device with extremely high reliability without deterioration of the device over time due to long-term driving, while keeping the driving voltage low.

In this example, a PLZT flat plate with a thickness of 400 μm was used, and photolithography technology was used.

The PLZT flat plate 11 was etched by a chemical etching method to form grooves for the electrode placement portions.

The etching depth of PLZT was about 2 μm.

Thereafter, Cr-Mom U was deposited on the entire surface as an electrode, and again by photolithography, a plurality of electrodes were formed to completely cover the PLZT etched portion. At this time, the electrode thickness of Or-mu U was about 1 μm. In addition, in FIG. 2a, the voltage application electrode group 13 had an electrode width of 50 μm, an electrode spacing of 70 μm, and an electrode spacing of the optical shutter section of 40 μm. At this time, in both the case of the optical shutter array element according to the present invention and the optical shutter 7-ray element of the conventional configuration, the transmittance of the optical shutter section reached the maximum at an applied voltage of 70 V. Furthermore, for the optical shutter array element according to the present invention and the optical shutter array element of the conventional configuration, 70V, I K11z
As a result of investigating the changes in each element over time when applying a square wave pulse of
There was a crack in the thick part of Figure 1, and the element deteriorated.
In the device structure of the present invention, even after driving for 2000 hours,
No change was observed, and stable transmittance was obtained.

In this example, Or-mu U was used as the electrode material, but it is easily assumed that similar effects can be obtained with other electrode materials. Furthermore, although the grooves for arranging the electrodes on the PLZT flat plate were formed by chemical etching, physical etching or mechanical methods may also be used (1), and the present invention is not limited thereto.

Effects of the Invention As is clear from the above description, the present invention provides a method of forming a plurality of electrodes on at least one surface of a solid plate-like translucent porcelain having an electro-optic effect so as to form a row of optical shutters. A polarizing plate is provided on the front and back sides of the flat plate so that the polarizing axes thereof are 90 degrees to each other.
The optical shutter array element is arranged at an angle of .degree., wherein a groove for arranging an electrode is provided at the electrode arranging position of the plate-shaped translucent porcelain, and the electrode is arranged at least on the wall surface of the groove. By having a structure in which resin is formed over the surface of the plate-shaped translucent porcelain connected to the groove wall surface, and also over a part of the electrode section and the optical shutter section connected thereto, when a voltage is applied, an electric current is generated. This is a highly reliable optical shutter array element that alleviates the concentration of distortion caused by distortion phenomena, eliminates deterioration due to mechanical destruction of the element due to long-term operation, and realizes low-voltage operation. The above-mentioned optical control devices and optical information processing technologies are attracting increasing attention for development in the future. The optical shutter array element of the present invention having the above properties provides great effects.

[Brief explanation of the drawing]

FIG. 1a is a configuration diagram of a conventional optical shutter array element.
FIG. 1 is a local sectional view thereof, FIG. 2a is a configuration diagram of an optical shutter array element according to an embodiment of the present invention, and FIG. 2 is a local sectional view thereof. 1... Flat plate at PI and Z, 2... Common electrode, 3... Voltage application electrode group, 4...
Polarizer, 6...Analyzer, 11...PL
ZT flat plate, 12... Common electrode, 13...
・Voltage application electrode group, 14...Insulating resin film, 1
5...Polarizer, 16...Analyzer. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure ((L)? (1P) Figure 2 (α mule

Claims (1)

[Claims] A plurality of electrodes are provided on at least one surface of a solid plate-shaped translucent porcelain having an electro-optical effect so as to form an optical shutter row, and polarizing plates are placed on the front and back surfaces of the flat plate so that the polarization axes thereof are 90 degrees to each other. an optical shutter array element arranged so as to form an angle of An optical shutter array element characterized in that it has a structure in which a resin is formed over the surface of the plate-shaped translucent porcelain connected to the groove wall surface, and also over a part of the electrode section and the optical shutter section connected thereto.